No-Moving-Part Valves

Microvalve No-moving-part valves Piezoelectric pumps... 

Izzo I, Accoto D, Menciassi A, Schmitt L, Dario P (2007) Modeling and experimental validation of a piezoelectric micropump with novel no-moving-part valves. Sens Actuators A 133(1) 128-140... 

Microvalve Piezoelectric pumps No-moving-part valves Definition... 

The reversibility of the metal-hydrogen reaction (Eq. l) and the heat of chemical reaction (Eq. 2) provides the basis for hydride heat pumps. These devices are closed units in which hydrogen serves as an energy carrier between two or more hydride beds. By selecting appropriate hydriding alloys, heat sources and heat sinks, heat can be pumped over wide temperature differentials with no moving parts except possibly check valves. 

In a vapor-absorption refrigeration system, there are no moving parts. The added energy comes from a gas or liquid fuel burner or from an electrical heater, as heat. rather than from a compressor, as work. See Fig. 2. The refrigerant used in this example is ammonia gas. which is liberated from a water solution and transported from one region to another by the aid of hydrogen, The total pressure throughout the system is constant and therefore no valves axe needed. 

To achieve a pressure balance, Reh did not require a standpipe of considerable height. Providing a slide valve for his operating temperature, 1,100°C, might be difficult, and he elected a device with no moving parts, the J-leg, for balancing the pressure drop across his fast bed. 

Check valves prevent back flow. The ball check valve, shown in Figure 8.3, is particularly simple in that it has no moving parts requiring close clearances bet-... 

The burner tip has no moving part, then its adjustment is done by three butterfly valves installed on the cold end of burner. The main burner concept of the burner tip is to have the PF channel located in between two streams of swirling air (Figure 31.13). The multi-channels are positioned as follows ... 

Throttling maybe viewed as expansion in a turbine that is so irreversible that no work is produced. Why should one waste the potential of a pressurized gas by throttling it rather than using a turbine to expand it Because using a valve is much cheaper to install and maintain (no moving parts) than a turbine. Replacing a throttling valve with a turbine will increase the efficiency of a process, but the decision to replace it would have to be made on a case-by-case basis, based on cost-benefit analysis. 

Small fluid flows used in the no-moving-part fluidic and microfluidic valves to ensure no cross-contamination takes place between various fluids leaving the valves into a common vent... 

Valve-Less Rectification Pumps, Fig. 16 Tesla diode, the earliest no-moving-part device designed to exhibit a large difference between the properties in forward and return flow direction. While the forward flow left, top) is almost straight, the reverse flow right, bottom) enters the complex curved flowpath. Diodity, even in the typical multi-stage layout, is not high, much worse than obtainable with vortex-type fluidic diodes... 

Valve-Less Rectification Pumps, Fig. 28 Forward-flow diverting by Coanda-effect attachment to a curved wall. This is the operating principle used in the no-moving-part peristaltic pump [9] or blower [14] for pumping dangerous fluids... 

Fluidic diodes and vortex valves are passive devices whose use in future nuclear power plants (NPPs) is currently under evaluation with reference to their potential use as check valves or actuation valves in safety-related systems. Fluidic diodes, used in reprocessing plants and chemical industries, are one-way valves with no moving parts. They are characterized by a very high flow resistance in one... 

One of the outstanding features of the CAREM reactor is that its safety systems are passive, which means that they have no moving parts except for valves and switches. This characteristic has as a consequence a qualitative improvement in reliability. Another of its consequences is that the safety systems do not require electric power, thus eliminating the need for safety grade Diesel generators. 

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